Crankshaft And Balancer; Balancer Shaft Inspection; Shaft End Float Measurement And Shim Selection - Polaris 1999 Sportsman 400 Service Manual

ENGINE LOWER END
163
CRANKSHAFT AND BALANC ER
1. Nut
2. Washer
3. Slotted nut
4. Camsh aft dr ive gear
5. Spacer
6. Balancer drive gea r
7. Key
B.
Woodruff
key
11
a
12 13
~
9. Cranks haft No.1
10. Needle beari ng
11. Connectin g ro d
12. Crankpin
13. Cran kshaft NO.2
14. Dowel pi n
15. Spacer
16. Balan cer shaft
5. Measure the connecting rod piston pin bore di-
ameter (Figu re 104) with a telesco ping gauge or in-
side micro meter and chec k aga inst the specifi cation
listed in Ta hle 2. Replace the connecting rod or the
cra nkshaft
if the dia
meter exceeds the new d imen-
sion.
6. Check the crankshaft bearing j ourn als (Figu re
105) for scratches. heat distortion or other defects.
7. Check the threaded
portions
(Figure 1(6) for
wear or damage. Repai r the thread s if necessary.
8. Inspect the balancer gear (Figur e 1( 7) for worn,
ch ipped
Of
missing tee th. If an y L eeth arc da maged,
also check the teeth on the balancer gear. The gear is
pressed onto the crank shaft and
if
damag ed, it can
be replaced .
BALANCER SHAFT INSPECTION
I.
Inspect the
balancer
shaft
bearing
jo urnals (F ig-
ure 108) for dee p sco ring, excessive weal' , heat dis-
tortion or cracks.
2. Inspect the gears (Figure 1(9) for
1V0m,
chipped
or missing teeth.
J
f
any teeth are damaged, also
check the balancer gear teeth on the cranksha ft,
3. Replace the balancer shaft
if it
is damaged.
SIIAFT END FLO AT MEASU REMENT
AND SIIIM SELECTI ON
note
The fo llo wing
measurements mus t be
accurate to avoid damage to the inter-
nul
components
ofthe crankcase. A
machin ed straightedge and an accu-
rate dial-typ e vernier calipe r is re-
quired for this procedure (Figure
110). If the measuring equipment is